Remember Blue Peter's competition to design sonic devices for Doctor Who's Paternoster Gang? In this Blue Peter special, Lindsey goes behind the scenes with the winners to see their Sonic Gauntlet, Lorgnette and Hat Pin in action - and they only run into Peter Capladi, the new Doctor, himself! Plus Dan Starkey, who plays Strax, explains how the show's prosthetics turn him into a Sontaran - and the make-it is a Tardis T-shirt.